A Pulsar has Been Found Turning so Slowly Astronomers Didn't Even Think it was Possible: Once Every 76 Seconds

Astronomy is progressing rapidly these days, thanks in part to how advances in one area can contribute to progress in another. For instance, improved optics, instruments, and data processing methods have allowed astronomers to push the boundaries of optical and infrared to gravitational wave (GW) astronomy. Radio astronomy is also advancing considerably thanks to arrays like the MeerKAT radio telescope in South Africa, which will join with observatories in Australia in the near future to create the Square Kilometer Array (SKA).

In particular, radio astronomers are using next-generation instruments to study phenomena like Fast Radio Bursts (FRBs) and neutron stars. Recently, an international team of scientists led by the University of Manchester discovered a strange radio-emitting neutron star with a powerful magnetic field (a “magnetar”) and an extremely slow rotational period of 76 seconds. This discovery could have significant implications for radio astronomy and hints at a possible connection between different types of neutron stars and FRBs.

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New Radio Images of Bizarre “Odd Radio Circles” Which are Vastly Bigger Than the Milky Way

Artist depiction of an Odd Radio Circle. Credit: CSIRO

In radio astronomy, circle-shaped objects are fairly common. Since diffuse ionized gas often emits radio light, objects such as supernova remnants, planetary nebulae, and even star-forming regions can create circular arcs of diffuse gas. But in 2019 astronomers began to discover radio circles they couldn’t explain, in part because they are so large.

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Imaging the Galaxy’s Centre in Unprecedented Detail Reveals More Mysterious Filaments

Milky Way centre by the MeerKAT array of 65 radio dishes in South Africa. The image spans 4 times the Moon's size in the sky. Ian Heywood (Oxford U.), SARAO; Here is a full sized version of the picture (which you have to check out!) that was posted in Astronomy Picture of the Day. Colour processing on the image was done by Juan Carlos Munoz-Mateos (ESO) whose Instagram channel you should definitely check out. Has some of the coolest astro images I've seen.

The inner 600 light years of our galaxy is a maelstrom of cosmic radiation, turbulent swirling gas clouds, intense star formation, supernovae, huge bubbles of radio energy, and of course a giant supermassive black hole. This bustling downtown of the Milky Way is a potential treasure trove of discovery but has been difficult to study as the galaxy’s central regions are obscured by dust and glaring radiation. But a new image of this region with unprecedented detail reveals more than we’ve ever seen before. We find some familiar objects like supernovae but also some mysterious structures – gaseous filaments dozens of light years long channeling electrons at near light speed.

Behold, the galaxy’s centre as never seen before:

The new MeerKAT image of the Galactic centre region is shown with the Galactic plane running horizontally across the image. Many new and previously-known radio features are evident, including supernova remnants, compact star-forming regions, and the large population of mysterious radio filaments. Colours indicate bright radio emission, while fainter emission is shown in greyscale. Credit: I. Heywood, SARAO. Image description: SARAO
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What’s Causing the Mysterious Radio Waves Coming From the Center of the Milky Way?

An artist's impression of ASKAP J173608.2-321635, the mysterious radio source at the center of the Milky Way. Image Credit: Sebastian Zentilomo.

The center of the Milky Way is a mysterious place. Astronomers think there’s a supermassive black hole there, though it could be dark matter instead. The region is densely packed with stars, dominated by red giants. And because of all the dust between Earth and the galactic center, we can’t see anything with visible light, ultraviolet light, or low-energy x-rays.

But we can detect radio waves, and there are some unexplained ones coming from the center of the galaxy, and adding to the mystery.

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The Square Kilometer Array has Gotten the Official Green Light to Begin Construction

omposite image of the SKA combining all elements in South Africa and Australia. CreditL SKAO

In Australia and South Africa, there are a series of radio telescopes that will be soon joined by a number of newly-constructed facilities to form the Square Kilometer Array (SKA). Once established, the SKA will have a collecting area that measures a million square meters (close to 2 million square yards). It will also be 50 times more sensitive than any radio telescope currently in operation, and be able to conduct surveys ten thousand times faster.

During a historic meeting that took place on June 29th, 2021, the member states that make up the SKAO Council voted to commence construction. By the late 2020s, when it’s expected to gather its first light, the array will consist of thousands of dishes and up to a million low-frequency antennas. These will enable it to conduct all kinds of scientific operations, from scanning the earliest periods in the Universe to searching for extraterrestrial intelligence (SETI).

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New Mosaic Shows the Galactic Core From Opposite Sides of the Electromagnetic Spectrum

Credit: X-ray: NASA/CXC/UMass/Q.D. Wang; Radio: NRF/SARAO/MeerKAT)

The core of the Milky Way Galaxy (aka. Galactic Center), the region around which the rest of the galaxy revolves, is a strange and mysterious place. It is here that the Supermassive Black Hole (SMBH) that powers the compact radio source known as Sagittarius A* is located. It is also the most compact region in the galaxy, with an estimated 10 million stars within 3.26 light-years of the Galactic Center.

Using data from Chandra X-ray Observatory and the MeerKAT radio telescope, NASA and the National Research Foundation (NSF) of South Africa created a mosaic of the center of the Milky Way. Combining images taken in the x-ray and radio wavelengths, the resulting panoramic image manages to capture the filaments of super-heated gas and magnetic fields that (when visualized) shows the complex web of energy at the center of our galaxy.

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Want to Find Aliens? The Largest Dataset in the History of SETI has Been Released to the Public

Credit: Breakthrough Listen

In 2016, Russian-Israeli billionaire Yuri Milner launched Breakthrough Initiatives, a massive non-profit organization dedicated to the search for extra-terrestrial intelligence (SETI). A key part of their efforts to find evidence of intelligent life is Breakthrough Listen, a $100 million program that is currently conducting a survey of one million of the nearest stars and the 100 nearest galaxies.

In keeping with their commitment to making the results of their surveys available to the public, the Listen team recently submitted two papers to leading astrophysical journals. These papers describe the analysis of Listen’s first three years of radio observations which resulted in a petabyte of radio and optical data, the single largest release of SETI data in the history of the field.

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A Magnetar Just Woke Up After Three Years of Silence

Aerial image of the South African MeerKAT radio telescope, part of the Square Kilometer Array (SKA). Credit: SKA

When stars reach the end of their main sequence, they undergo a gravitational collapse, ejecting their outermost layers in a supernova explosion. What remains afterward is a dense, spinning core primarily made up of neutrons (aka. a neutron star), of which only 3000 are known to exist in the Milky Way Galaxy. An even rarer subset of neutron stars are magnetars, only two dozen of which are known in our galaxy.

These stars are especially mysterious, having extremely powerful magnetic fields that are almost powerful enough to rip them apart. And thanks to a new study by a team of international astronomers, it seems the mystery of these stars has only deepened further. Using data from a series of radio and x-ray observatories, the team observed a magnetar last year that had been dormant for about three years, and is now behaving somewhat differently.

The study, titled “Revival of the Magnetar PSR J1622–4950: Observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR“, recently appeared in The Astrophysical Journal. The team was led by Dr Fernando Camilo – the Chief Scientist at the South African Radio Astronomy Observatory (SARAO) – and included over 200 members from multiple universities and research institutions from around the world.

Magnetars are so-named because their magnetic fields are up to 1000 times stronger than those of ordinary pulsating neutron stars (aka. pulsars). The energy associated with these these fields is so powerful that it almost breaks the star apart, causing them to be unstable and display great variability in terms of their physical properties and electromagnetic emissions.

Whereas all magnetars are known to emit X-rays, only four have been known to emit radio waves. One of these is PSR J1622-4950 – a magnetar located about 30,000 light years from Earth. As of early 2015, this magnetar had been in a dormant state. But as the team indicated in their study, astronomers using the CSIRO Parkes Radio Telescope in Australia noted that it was becoming active again on April 26th, 2017.

At the time, the magnetar was emitting bright radio pulses every four seconds. A few days later, Parkes was shut down as part of a month-long planned maintenance routine. At about the same time, South Africa’s MeerKAT radio telescope began monitoring the star, despite the fact that it was still under construction and only 16 of its 64 radio dishes were available. Dr Fernando Camilo describes the discovery in a recent SKA South Africa press release:

“[T]he MeerKAT observations proved critical to make sense of the few X-ray photons we captured with NASA’s orbiting telescopes – for the first time X-ray pulses have been detected from this star, every 4 seconds. Put together, the observations reported today help us to develop a better picture of the behaviour of matter in unbelievably extreme physical conditions, completely unlike any that can be experienced on Earth”.

Artist’s rendering of an outburst on an ultra-magnetic neutron star, also called a magnetar. Credit: NASA/Goddard Space Flight Center

After the initial observations were made by the Parkes and MeerKAT observatories, follow-up observations were conducted using the XMM-Newton x-ray space observatory, Swift Gamma-Ray Burst Mission, the Chandra X-ray Observatory, and the Nuclear Spectroscopic Telescope Array (NuSTAR). With these combined observations, the team noted some very interesting things about this magnetar.

For one, they determined that PSR J1622-4950’s radio flux density, while variable, was approximately 100 times greater than it was during its dormant state. In addition, the x-ray flux was at least 800 times larger one month after reactivation, but began decaying exponentially over the course of a 92 to 130 day period. However, the radio observations noted something in the magnetar’s behavior that was quite unexpected.

While the overall geometry that was inferred from PSR J1622-4950’s radio emissions was consistent with what had been determined several years prior, their observations indicated that the radio emissions were now coming from a different location in the magnetosphere. This above all indicates how radio emissions from magnetars could differ from ordinary pulsars.

This discovery has also validated the MeerKAT Observatory as a world-class research instrument. This observatory is part of the Square Kilometer Array (SKA), the multi-radio telescope project that is building the world’s largest radio telescope in Australia, New Zealand, and South Africa. For its part, MeerKAT uses 64 radio antennas to gather radio images of the Universe to help astronomers understand how galaxies have evolved over time.

Aerial image of the South African MeerKAT radio telescope in the Karoo, South Africa. Credit: SKA

Given the sheer volume of data collected by these telescopes, MeerKAT relies on both cutting edge-technology and a highly-qualified team of operators. As Abbott indicated, “we have a team of the brightest engineers and scientists in South Africa and the world working on the project, because the problems that we need to solve are extremely challenging, and attract the best”.

Prof Phil Diamond, the Director-General of the SKA Organization leading the development of the Square Kilometer Array, was also impressed by the contribution of the MeerKAT team. As he stated in an SKA press release:

“Well done to my colleagues in South Africa for this outstanding achievement. Building such telescopes is extremely difficult, and this publication shows that MeerKAT is becoming ready for business. As one of the SKA precursor telescopes, this bodes well for the SKA. MeerKAT will eventually be integrated into Phase 1 of SKA-mid telescope bringing the total dishes at our disposal to 197, creating the most powerful radio telescope on the planet”.

When the SKA goes online, it will be one of the most powerful ground-based telescopes in the world and roughly 50 times more sensitive than any other radio instrument. Along with other next-generation ground-based and space-telescopes, the things it will reveal about our Universe and how it evolved over time are expected to be truly groundbreaking.

Further Reading: SKA Africa, SKA, The Astrophysical Journal

Weekly Space Hangout – May 27, 2016: Dr. Seth Shostak

Host: Fraser Cain (@fcain)

Special Guest:
Dr. Seth Shostak is the Senior Astronomer at the SETI Institute. He also heads up the International Academy of Astronautics’ SETI Permanent Committee. In addition, Seth is keen on outreach activities: interesting the public – and especially young people – in science in general, and astrobiology in particular. He’s co-authored a college textbook on astrobiology, and has written three trade books on SETI. In addition, he’s published more than 400 popular articles on science — including regular contributions to both the Huffington Post and Discover Magazine blogs — gives many dozens of talks annually, and is the host of the SETI Institute’s weekly science radio show, “Big Picture Science.”

Guests:
Paul M. Sutter (pmsutter.com / @PaulMattSutter)
Kimberly Cartier (@AstroKimCartier )
Jolene Creighton (fromquarkstoquasars.com / @futurism)
Nicole Gugliucci (cosmoquest.org / @noisyastronomer)
Brian Koberlein (@briankoberlein / briankoberlein.com)

Their stories this week:
“Fresh” Lunar Craters

Faintest early-universe galaxy detected

Update on NASA’s Juno Mission

Europa’s ocean may have Earth-like chemical balance

Do Primordial Black Holes Solve Dark Matter?

India Successfully Launches Tiny Reusable Space Shuttle

30 KM Wide Asteroid Impacted Australia 3.4 Billion Years Ago

MeerKAT First Images

We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.

You can also join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+!

Supermassive Black Holes In Distant Galaxies Are Mysteriously Aligned

A supermassive black hole has been found in an unusual spot: an isolated region of space where only small, dim galaxies reside. Image credit: NASA/JPL-Caltech
A team of astronomers from South Africa have noticed a series of supermassive black holes in distant galaxies that are all spinning in the same direction. Credit: NASA/JPL-Caltech

In 1974, astronomers detected a massive source of radio wave emissions coming from the center of our galaxy. Within a few decades time, it was concluded that the radio wave source corresponded to a particularly large, spinning black hole. Known as Sagittarius A, this particular black hole is so large that only the designation “supermassive” would do. Since its discovery, astronomers have come to conclude that supermassive black holes (SMBHs) lie at the center of almost all of the known massive galaxies.

But thanks to a recent radio imaging by a team of researchers from the University of Cape Town and University of the Western Cape, in South Africa, it has been further determined that in a region of the distant universe, the SMBHs are all spinning out radio jets in the same direction. This finding, which shows an alignment of the jets of galaxies over a large volume of space, is the first of its kind, and could tell us much about the early Universe.

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